La gestión espacial de la pesquería de merluza en el Mediterráneo catalán: Simulación del efecto de diferentes alternativas de gestión en base del Modelo InVEST

Hake (Merluccius merluccius) is one of the most important demersal species in the Mediterranean ecosystem. This species of an important commercial value shows a growth overexploitation with catches basically focused on juveniles. Considering the interest of spatial management for the sustainability of Mediterranean fisheries, this study assesses the benefit of closing a shallow area to fishing (essential habitat for hake recruits) and the consequences of diverse spatial and non-spatial management scenarios applied to the hake fishery, precisely in the province of Girona (Ports of Blanes and Palamós). We use InVEST, a model of intermediate complexity (MMR) and spatially explicit that allows the simulation of the bioeconomic effects of such management measures for decision making. The sensitivity analysis of the model shows the high influence of some parameters, mainly the parameterization of the Recruitment submodel and hake’s fecundity coefficients. We treat the results in two parts, the first part con less uncertainty while the second part integrates the migrations by age of hake based on bibliographical data. The main management scenario evaluated in this work is manifested by the closure of the fishing ground "Vol de terra", as a measure of recovery of the hake fishery in the study area. This scenario represents a proposal from the fishery sector resulting from a consultative approach with the other stakeholders, and the present study represents a scientific contribution towards the objective of pre-evaluating this management measure and supporting its eventual implementation planned for 1 January 2018. Given the parameterization of the model with the required biological and fishery exploitation data, the actual interest of the Marine Protected Area (MPA) "Vol de terra" is concluded among the other scenarios studied. In the two cases analyzed (considering or not migration patterns), the results of the different indicators (catch and revenues, abundance, recruitment and SSB) were qualitatively similar and all show that the application of a MPA in "Vol de Terra" represents the best management alternative and that its effect corresponds to a reduction of fishing effort up to 20%. The second case (with migration) highlights, as well, the interest of closing the fishing ground "CuldeRecElPas" with a significant effect on the hake population, underlining the interest of improving the knowledge on the hake migration patterns in the Catalan Sea.